Abstract： Objective To investigate the effect of chemotherapy regimen of rituxmab combined with CHOP (R-CHOP) on the survival of patients with diffuse large B cell lymphoma (DLBCL). Methods One hundred and fifty-six cases of DLBCL diagnosed according to the WHO 2008 classification were collected from the haematopathological laboratory, the department of pathology, and Beijing University Health Science Center. Standard two-step method of immunohistochemical staining with Envision was used to assess the expression of CD10, MUM-1, bcl-6, and bcl-2. The different classification models were made according to the immuaohistochemical staining results. Hans algorithm classifies the patients into two subgroups originating from germinal center B cell-like cell (GCB) and non-germinal center B cell-like cell (non-GCB), and Muris model were classfied the DLBCL patients into the good-survival groupl and the poor-survival group2. Thirty patients with treatment of R-CHOP were set as study group and the other 126 patients without Retuxmab were defied as control group. The data were analyzed with X2 test, log-linear model and Life Table survival analysis by the SAS 8.2 statistical package. Results The 3-year survival rate of the study group was 78.3 %, but was 53.4 % in the control group. The over-all survival of the study group was obviously better than the control group with the significant difference (P <0.05). Hans algorithm showed no implication of survival for any group. The survival of different groups in Muris model has no difference in study group but was obvious in control group. The expression of bcl-2 protein has no association with survival in study group but acted as a worse implication of survival in control group. Conclusion R-CHOP chemotherapy regimen could improve the remission rate and over-all survival of DLBCL. Rituxmab could weaken the effect of bcl-2 expression in the prognosis, and the implication of survival by Muris model has diminished.